Computer tomography methods for creation of section images with the aid of multiple focus detector combinations are known, for example, from the patent specifications U.S. Pat. No. 4,196,352, U.S. Pat. No. 4,384,359, U.S. Pat. No. 5,966,422, U.S. Pat. No. 4,991,190 and U.S. Pat. No. 6,421,412 B1. The Laid-Open Specification DE 199 57 082 discloses the recording of movement signals of the heart by use of an EKG in order to display a beating heart in parallel with the scanning process, in order that the rest phases of the heart can be determined and in order that exclusively images from the rest phase can be assessed, with the X-ray source additionally being active only during the rest phase in the cited document.
However, the documents cited above in principle make use of spiral reconstruction methods which are based on a complete 180° spiral data record. This means that a large amount of measurement information cannot be used since only measurement data at the correct time. That is to say, data measured in the same heart phase, can be used. This data jointly results in a 180° spiral data record.
The Laid-Open Specification DE 10 127 269 A1 discloses how segment images are created from incomplete spiral data records which intrinsically include only a portion of a 180° segment of a spiral scan. These segment images then lead to complete CT scan images by addition of a number of segment images in a segment stack. Laid-Open Specification DE 10 133 237 A1 also discloses the application of the abovementioned SMPR (Segmented Multiple Plane Reconstruction) method for the display of periodically moving objects, although the cited document describes only a solution for a CT scanner with a single revolving focus. Another similar method is the ACMPR (Adaptive Cardio Multiple Plane Reconstruction) method, which is a generalization of the SMPR method with the segment length additionally being variable.
With regard to the SMPR method, reference should be made to the document by Stierstorfer, Flohr, Bruder: Segmented Multiple Plane Reconstruction: A Novel Approximate Reconstruction Scheme for Multislice Spiral CT., Physics in Medicine and Biology, Vol. 47 (2002), pp. 2571–2581. With regard to this ACMPR method, reference should be made to the literature reference T. Flohr, B. Ohnesorge, ‘Heart-Rate Adaptive Optimization of Spatial and Temporal Resolution for ECG-Gated Multislice Spiral CT of the Heart’, JCAT vol. 25, No. 6, 2001, and to H. Bruder et al., ‘A Novel Reconstruction Scheme for Cardiac Volume Imaging with MSCT Providing Cone Correction’, Medical Imaging 2002, Image Processing, Vol 4684, pp. 60–72. The disclosure content of both documents is hereby incorporated herein by reference, in their entirety.
The problem of these known and so-called SMPR—or ACMPR—methods is that the time resolution that is achieved when scanning a periodically moving heart is not sufficient to achieve sufficiently sharp image representations.